This invention relates to a liquid crystal display (LCD) device and to a method of manufacturing the same.
In the manner which will later be described in greater detail with reference to about a dozen of accompanying drawing figures, known are various liquid crystal devices in which a layer of a liquid crystal (LC) material is divided into a plurality of layer domains per pixel. When supplied with an electric voltage, the pixels show different contrast to provide a display of a pattern dependent on the voltage applied across each pixel. Such a multi-domain liquid crystal display device has a wide viewing angle of the display with an excellent contrast between those parts of the display which the pixels may correspond to either from pixel to pixel or from pixels of a segment to pixels of a background of the display.
The multi-domain liquid crystal display comprises first and second substrate members and the layer of liquid crystal display material between the first and the second substrate members. It will be presumed without loss of generality that the display is viewed by watching the first substrate member with the voltage applied across the first and the second substrate members. The pixels are usually defined by the second substrate member. Each substrate member comprises an alignment film in contact with the liquid crystal material. The layer domains are provided by processing the alignment films of the first and the second substrate members locally different in each pixel.
In each of such domains, the liquid crystal material has orientations which depend primarily on manners of processing the alignment films. Irrespective of the manners of processing, the orientations are subjected to a twist even when no voltage is applied across the first and the second substrate members. The twist results in a twist angle between the alignment films of the first and the second substrate members. Furthermore, the liquid crystal material has a chiral pitch specific to the material in a direction perpendicular to the first and the second substrate members when no voltage is applied between the substrate members.
As will be pointed out with reference to a few of the accompanying drawing figures later before describing this invention in detail, it has been confirmed by the present inventor that the layer domains have energy whose stability depends on the twist angle in each of the layer domains. This stability depends also on the chiral pitch. The viewing angle and the contrast primarily depend accordingly on the twist angle and the chiral pitch among others.